Photographic materials for the silver-dye-bleach process

ABSTRACT

CERTAIN AZO DYES OR THEIR MESOMERIC AZINE DYES ARE PARTICULARLY SUITED AS SILVER-DYE-BLEACH DYES. THE LIGHTSENSITIVE EMULSION USED TO CARRY THE DYES CAN CONTAIN THE DYES THEMSELVES OR ONE OR MORE COMPONENTS THAT WILL REACT TO FORM THE DYES SUBSEQUENTLY, AS DURING THE PROCESSING.

United States Patent Int. Cl. GilSc 1/10 U.S. Cl. 96-99 3 ClaimsABSTRACT OF THE DISCLOSURE Certain azo dyes or their mesomeric azinedyes are particularly suited as silver-dye-bleach dyes. Thelightsensitive emulsion used to carry the dyes can contain the dyesthemselves or one or more components that will react to form the dyessubsequently, as'during the processmg.

The invention relates to photographic materials for the silver dyebleach process, which materials contain certain azo dyes or theirmesomeric azine dyes, these dyes having excellent spectral propertiesand high brilliance.

It is known that color photographic images can be produced by thesilver-dye-bleach process, wherein a dye, usually an azo dye, isbleached in a homogeneously dyed colloid layer in accordance with asilver image which has been produced photographically.

According to this process, it is possible to produce both negatives andreversal images. If it is desired toproduce positive paper prints orduplicate positives from diapositives, the silver image is produced bymeans of a simple black-and-white development, this silver imagerepresenting a negative of the copying original. Since the image dyewhich is homogeneously distributed in the layer (or in the 3 layers of amulticolor material) is bleached proportionately to the silver image, adye image is obtained, which is positive with respect to the original.If a silver image is produced which is positive with respect to theoriginal, for example, by a black-and-white reversal development or bythe bromide ion diffusion method or silver salt diifusion method, thenafter the color bleaching a dye image is formed which is opposite ingradation to the original that is to say a positive color image isformed if the original is a negative color image.

The standards set as regards dyes for the process described areparticularly high, since these dyes must be spectrally suitable, andshould also be easily bleachable and fast to light. Furthermore, theymust not detrimentally affect the photographic emulsion and must becompletely resistant to ditfusion in the gelatin, which is almostexclusively used as layer former. It is particularly important to have ahigh degree of fastness to light, and resistance to acid gases, such asoccur, for example, in industrial atmospheres.

It has now been found that azo dyes or their mesomeric 3,561,970Patented Feb. 9, 1971 azine dyes of the following general formulae areespecially suitable for this purpose:

R-A-N=NB (or its mesomeric azine form RlA=N-N=B wherein: A=(I) aryl suchas phenylene or naphthylene, (II) a S-membered or 6 memberedheterocyclic ring with preferably nitrogen as a heterocyclic ringmember, such as pyrazolone or thiazole; the above groupings particularlythe phenyl rings can in turn be substituted, for example, with halogensuch as chlorine or bromine, alkyl such as methyl or ethyl withpreferably up to 5 carbon atoms, hydroxy, alkoxy having up to 5 carbonatoms such as methoxy or ethoxy, carboxyl, esterified carboxy, amino,a'cylamino preferably such as acetylamino or stearoylamino, alkylamino,sulfo, aminosulfonyl, esterified sulfo groups, alkylsulfonyl or thelike; or (III) a grouping of the formula:

in which R, stands for an aliphatic radical such as alkyl, or aromaticradical such as phenyl, which can be substituted with the aforementionedsubstituents, and R represents an electro-negative group which activatesmethylene groups, such as nitrile, CO or CS; R=hydroxyl, NHSO2R7 orwherein R represents alkyl with up to 8 carbon atoms,

aryl such as phenyl or naphthyl or aralkyl such as benzyl or phenylalkyl such as phenylethyl; R and R stand for hydrogen, alkyl with up to20 carbon atoms, aryl, more especially phenyl or naphthyl, aralkyl suchas benzyl or phenyl alkyl such as phenyl-ethyl or for a S-membered or6-membered heterocycilc ring such as pyridinyl or quinolinyl; thesegroups can be substituted in the manner indicated above; or thesubstituents R and R can represent the ring members necessary tocomplete a heterocyclic ring, preferably a saturated ring, such as, forexample, morpholine, piperidine, pyrrolidine, or piperazine;B=represents a grouping of the formula (or its mesomeric form wherein Yrepresents a chemical linkage, a vinylene grouping, an azomethinegrouping or a phenylene preferably a 1,2-phenylene group; in the case ofthe first-mentioned formula, Y is to be appropriately changed accordingto the bond displacements caused by the mesomerism, e.g. CH=CH CH CH=etc. X=alkyl, such as methyl, ethyl, butyl, hexyl, palmityl or stearyl,olefinically unsaturated alkyl such as allyl, aryl, preferably phenyl ornaphthyl, aralkyl such as benzyl or phenyl alkyl such as phenylethyl ora or 6-membered cycloalkyl such as cyclohexyl; the above groups,particularly the phenyl radicals, can be substituted, for example, withhalogen such as chlorine or bromine, alkyl such as methyl or ethyl withpreferably up to 5 carbon atoms, hydroxy, alkoxy having preferably up to5 carbon atoms, such as methoxy, ethoxy, carboxyl, esterified carboxy,amino, acylamino the acyl groups being preferably'defivedfrorn analiphatic carboxylic acid having up to 18' carbon atoms such asacetylamino or stearoylainiiio, alkylamino, sulfo, aminosulfonyl,esterified sulfo groups, alkylsulfonyl or the like; R hydrogen, alkylwith up to 20 carbon atoms, such as methyl, ethyl, butyl, stearyl,olefinically unsaturated alkyl, such as allyl, 5- or 6-memberedcycloalkyl such as cyclohexyl, aryl, preferably phenyl or naphthyl, oraralkyl such as benzyl or phenyl alkyl such as phenyl ethyl; R=hydrogen, alkyl with up to- 20 carbon atoms, such as methyl, ethyl,butyl, stearyl, olefinicall-y unsaturated alkyl, such as allyl, 5- or-6-membered cycloalkyl such as cyclohexyl, aryl, preferably phenylor-naphthyl, or aralkyl such as benzyl or phenylethyl, it being possiblefor the above groups and particularly the phenyl radicals to besubstituted, for example, with halogen such as chlorine or bromine,alkyl such as methyl or ethyl with advantageously up to 5 carbon atoms,hydroxy, alkoxy having preferably up to 5 carbon atoms such as methoxy,ethoxy, carboxyl, esterified carboxy, amino, acylamino, the acyl groupsbeing preferably derived from an aliphatic carboxylic acid having up to18 carbon atoms such as acetylamino or stearylamino, alkylamino, sulfo,aminosulfonyl, esterisulfo groups, alkylsulfonyl or the like; preferredare substituents which render the dyes fast to diffusion or soluble inwater; X and R and/or X and R together can in addition represent themethylene or rnethine groups or hetero atoms such as-O, S, Se-- or N--which are necessary for completing a simple or fused 5- membered or6-mernbered heterocyclic ring; the combina tion X+R can, for example,represent the ring members necessary for completing the followingheterocyclic rings: oxazole, benzoxazole, thiazole, benzthiazole,selenazole, benzselenazole, imidazole, benzirnidazole, pyrrolidone,quinoline, piperidine, pyrimidine; the combination X+R can represent thering members necessary for completing the following heterocyclic rings:piperidine, morpholine, pyrazole, pyrazoline, pyrrolidine andoxazolidine.

The phenyl or naphthyl rings and heterocyclic compounds of the generalforinula can, as already indicated, be substituted in any desiredmanner. Generally suitable substituents include halogen such as chlorineor bromine, alkyl or alkoxy with up to 2O carbon atoms, carboxyl,carboxyl esterifi'ecl with preferably aliphatic alcohols up to 20 carbonatoms, sulfo, sulforiamid'e or carbonamide, it being possible for theamide groups to' be substituted with alkyl radicals with up to 20 carbonatoms or acyl radicals, more especially those which are derived fromaliphatic carboxylic acids with up to 20 carbon atoms, as well as nitro,nitrile or amino groups. The amino group can in its turn be substitutedwith alkyl with up to 20 carbon atoms, acyl preferably 'acyl which isderived from aliphatic carboxylic acids with up to 20'c'arbonatoms orphenyl; the aromatic or heterocyclic radical of the above formula canfurthermore be substituted by further phenyl or also naphthyl rings orcan contain the latter in anellated form.

Also the substituents on the phenylene ring of the above formula can intheir turn be substituted, so that numerous possibilities of variationare provided, and certain properties such as solubility or the colour ofthe dyes can be modified as desired. Upon selection of the substituent,it is merely necessary to ensure that the resulting products 4 do nothave any negative influence on the photographic properties of thematerial, and, under the usual photographic processing conditions, donot react with developers or their oxidation products or at most onlywith the formation of colourless products.

The mesomerism between the azo and azine form which occurs with the dyesto be used for the inventive material is explained in the followingequations:

'B represents:

Cis as (3H3 V 3 i CH3 magenta f CHs l 6i T CH magenta orange bluemagenta yellow yellow magenta.

magenta,

blue 20 magenta magenta cyan where G represents:

magenta magenta a. 0 S w H x 2 a H H 0 m w m 2 H N O H C N] I F m a. m QS e r P e r L e r e h w 0 Ru 0 6 6 7 e a a u t ..L m w m g on a a m m m0 a 0 m S a C v H z H m P m C 0 C N 0 z m N I l l H\ O H\ C Q O S 02Hmagenta The above dyes and methods for the prepartion thereof have beenfrequently described in the literature. A comprehensive illustrationthereof is found in the publication by Hiinig, Angewandte Chemie, vol.70 (1958), pp. 215 et seq and in later publications, see LiebigsAnnalen,

vol. 651 (1962), pp. 89 et seq. Other literature references process. Asshown in the following examples, they are used preferably as image dyesin layers which are subjected to a simple black-and-white negativedevelopment and thus lead to direct positive dye images in thesubsequent dye bleaching bath. However, one could equally well perform ablack-and-white reversal development, and after passing the film throughthe treatment baths of the silver dye bleach-process, dye images areobtained which have a characteristic curve opposite to that of theoriginal such as required for the production of positive colored printsor transparencies starting from a color negative.

The dyes mentioned above are largely inert to the usual quantities ofemulsion additives such as optical or chemical sensitizers, stabilizers,plasticizers, wetting agents, hardening agents and other substances.

As will be shown in the examples given below, they can be bleached topure whites in different types of bleaching baths, e.g., those based onquinoline and iodide (as described in US. Pat. No. 2,629,568, Examplea29) or those based on thiourea (as in British Pat. No. 507,211) andwith the use of different bleaching catalysts such as quinoxalines,phenazine derivatives and the like.

The dyes to be used according to-the-invention can be added to all typesof silver halide emulsions such as silver chloride, silver: bromide,silver chlorobromide or emulsions which contain a small amount of, forexample, up to 10 mole percent of silver iodide.

Color photographic layers containing the azo dyes of the'presentinvention can be applied onto any support such as paper, baryta-coatedpaper, polyethylene coated paper or paper which has in some other waybeen rendered hydrophobic, glass, metallized foils of all types,cellulose acetates, in paiticular cellulose triacetate, in transparentor White pigmented form. They can also be cast on backed, transparent onpigmented foils of polyesters, especially polyethylene terephthalate,polycarbonates and other polyesters.

In accordance with another embodiment of the present invention, only onecomponent for the production of the azo dyes is incorporated in thelight-sensitive silver halide emulsion layer and the azo dye .is thenproduced by treating such a layer under suitable conditions with asolution of the other component. It is likewise possible to incorporateboth components for the required azo dye into the light-sensitive layer.The layer is then treated with a suitable bath in order to cause thereaction of the two components to form the azo dye. The processing ofthe light-sensitive layer must be conducted in such a -way that thephotographic properties of the layer are not deleteriously effected. Thepreparation of the dye can be performed before or after exposure of thelight-sensitive layer or even after development of the exposed layer.The advantages of this embodiment of the invention lies in theparticularly fine distribution of the dye formed in the light-sensitivelayer.

8 EXAMPLE 1 1.4 g. of the hydrazoneiof the following formula:

(CHghrCH:

are incorporated, together wtihl 1.3- g. of a compound of the followingformula:

0 l C lB 37 in 100 cc. of a gelatine silver bromide emulsion and appliedto a suitable support, e.g. acetylcellulose.

In the dried layer, the dye of the formula given below is produced byrinsing in a 10% potassium ferricyanide solution, the pH, value of whichhas been adjusted to 7.5.

The layer is then dried," whereafter it is exposed and further processedas follows.

(1) Development for 5 minutes at 20 C. in a developer of the followingcomposition:

1 g. of p-methylanrino phenol 10 g. of hydroquinone 10 g. of sodiumsulfite 12 g. of soda, anhydrous 1 g. of potassium bromide 1 litre ofwater.

50 cc. of ethanol 50 g. of thiourea 20 mg. of quinoxaline 910 cc. ofwater 5 cc. of concentrated sulfuric acid.

(6) Rinsed for 5 minutes (7) Bleach-fixed for 10 minutes in ableach-fixing bath of the following composition:

26 g. of tetrasodium-ethylenediamine-tetraacetate 24 g. of soda,anhydrous 15 g.- of ferricchloride, crystals 13 g. of sodium sulfite,dry

200 g. of sodium thiosulfate in 500 ml. of water.

(8) Rinsed for 20 minutes. A magenta-c0lored direct'positive image isobtained. It will readily be understoodthat bleaching baths of adifferent composition are also suitable for the process, for example:

200 ml. of 10% aqueous solution of potassium iodide 10 g. of sodiumhypophosfite 90 ml. of quinoline 22 mg. of quinoxaline and 300 ml. ofN-hydrochloric acid in 400 ml. of water.

EXAMPLE 2 To 100 cc. of a silver bromide gelatine emulsion are added anaqueous alkali solution of 1.5 g. of a dye of the following formula:

The emulsion thus prepared is applied onto a support, e.g. of celluloseacetate. The photographic layer obtained is exposed and processed inaccordance with Example 1. A yellow, direct positive image is obtained.

The dye of the indicated formula is prepared as follows:

17 g of 1-(4-methoxy 3 sulphophenyl) 3 heptadecyl 5 pyrazolone aredissolved in 1 litre of a 3% soda solution 18 g. of potassium persulfateare added and the solution thus formed has added thereto anothersolution of 6.5 g. of N-ethyl-benzthiazolone hydrazone in a 50 cc. ofmethanol. Temperature: 20 C., time for addition 2 minutes. Stirring iscontinued for 1 hour and semi-concentrated hydrochloric acid is thenadded until the pH value has fallen below 2. After 30 minutes, thesolution is suction-filtered, the solids so recovered Washed twice withwater and dried in vacuo. Yield: 22 g.

EXAMPLE 3 1.4 g. of the hydrazone of the following formula:

( 2)i4CHs are incorporated, together with 1.3 g. of a compound of thefollowing formula:

?H 03H A t- Q t i. V CE: Cis ar in 100 cc. of a gelatine-silver bromideemulsion and applied to a suitable support, e.g. acetylcellulose.

The dried layer is imagewise exposed and the exposed layer developed inthe developer bath of Example 1.

The thus developed layer is fixed with a 20% aqueous solution of sodiumthiosulfate and-after rinsingtreated for two minutes at a temperature of20 C. With an oxidising bath of the following composition:

30 g. of potassium persulfate g. of potassium ferricyanide 1 l. ofWater.

Thereafter the pH of the layer is adjusted to a value of 7 by treatmentwith an aqueous sodium carbonate solution. Subsequent dye-bleaching andbleach-fixing of the silver image is accomplished as described inExample 1.

The composition of the oxidising bath can be modified according to therequirements of the special photographic material. The only conditionwhich has to be met is that the silver image produced upon developmentmust not be bleached.

A magenta direct positive image is obtained.

What is claimed is:

1. Light-sensitive photographic material with at least one silver halideemulsion layer containing an azo dye which in one mesomeric form has theformula:

R--AN=N--B wherein A=a bivalent radical of the phenylene or naphthyleneseries or a bivalent heterocyclic ring selected of the group consistingof pyrazole and thiazole;

R=hydroxy,

R and R hydrogen, alkyl with up to 20 carbon atoms;

R =alkyl with up to 8 carbon atoms or a radical of the phenyl series;

B=a benzthiazolyl, benzimidazolyl or quinolyl or the group of thefollowing formula II N in which:

R =a radical of the phenyl or naphthyl series; R =alkyl with up to 20carbon atoms; X=alkyl with up to 18 carbon atoms.

2. In the process for the production of a silver-dyebleach photographicdye image the improvement according to which the silver-dye-bleach dyeis an azo or an azine dye which in one mesomeric form has the formula:

A=a bivalent radical of the phenylene or naphthylene series or abivalent heterocyclic ring selected of the group consisting of pyrazoleand thiazole;

R=hydroxy,

R and R =hydrogen, alkyl with up to 20 carbon atoms;

R =alkyl with up to 8 carbon atoms or a radical of the phenyl series;

B=a benzthiazolyl, benzimidazolyl, or quinolyl group or the group of thefollowing formula:

in which:

R =a radical of the phenyl or naphthyl series; R alkyl with up to 20carbon atoms; X=alkyl with up to 18 carbon atoms. 3. A process for theproduction of photographic dye images including the step of exposing tolight a supported light-sensitive silver halide emulsion layercontaining uniformly distributed there- 1- 1 in the components for theproduction of a dye which in one mesomeric form has the formula wherein:

A=a bivalent radical of the .phenylene .or naphthylene series or abivalent heterocyclic ring selected of the group consisting of pyrazoleand thiazole;

R hydroxy,

or 'NHSO2R7 R and-'=R =hydrogen, a-lkyl with up to 20 carbon atoms; R=alky1 with up to 8' carbonatomsor a radical of the phenyl series; B=abenzthiazolyl, benzimidazolyl, or quinoyl group or the group of thefollowing formula:

lie

12 inwhich:

R =a radical of the phenyl or naphthyl series;

R =alkyl with up to 20 carbon atoms; X=alkyl with up to 18 carbon atoms;

5 and then suitably processing the layer by development, dye-bleachingand fixing to obtain an image.

References Cited FOREIGN PATENTS 782,310 9/1957 Great Britain 8-46 OTHERREFERENCES Cornwelleclynez Colour Cinematography, p. 420,

Chapman & Hall, Ltd., London (1936).

Glauert et 211.: Journal Chemical Society, pp. 3742-6 (1953).

Hunig et a1.: Angewandte Chemie, v01. 70, pp. 215- 20 222(1958).

J. TRAVIS BROWN, Primary Examiner U.S.CI.X.R.

